Blog Birthday plugin for WordPress

This shows a simple message in the admin panel on their blog birthday.

> Happy 3rd Blogger Birthday! You’ve been around since 11 August 2008.

> Happy 7th Blog Birthday! The first post on this blog was on 19 November 2004.

> Happy 1st Blog Birthday! This blog was first registered on 23 July 2010.

### Caveat ###

– Old WordPress admin accounts have a registration date of 0000-00-00 and never have a
blogger birthday.
– Blog registration starts when you turn on WordPress multisite. If you did this, the
date may be off.
– First post assumes that there a post_id=1 and uses the date off that (for non-multisite installs).

### Thanks ###
This was inspired by the [@TwBirthday](http://twitter.com/TwBirthday) account on Twitter and [@dzver](http://twitter.com/dzver) for the idea.